# 遍历出key与value的元组
d = {10: "cat", 20: "dog"}
print(d)  # {10: 'cat', 20: 'dog'}
for i in d.items():
    print(i)
# 分别遍历出key与value
d = {10: "cat", 20: "dog"}
print(d)  # {10: 'cat', 20: 'dog'}
for key, value in d.items():
    print(key, value, sep="-->", end="\t")
